Mobile stroke care expedites intravenous thrombolysis and endovascular thrombectomy

BackgroundThe number of mobile stroke programmes has increased with evidence, showing they expedite intravenous thrombolysis. Outstanding questions include whether time savings extend to patients eligible for endovascular therapy and impact clinical outcomes.ObjectiveOur mobile stroke unit (MSU), based at an academic medical centre in upstate New York, launched in October 2018. We reviewed prospective observational data sets over 26 months to identify MSU and non-MSU emergency medical service (EMS) patients who underwent intravenous thrombolysis or endovascular thrombectomy for comparison of angiographic and clinical outcomes.ResultsOver 568 days in service, the MSU was dispatched 1489 times (2.6/day) and transported 300 patients (20% of dispatches). Intravenous tissue plasminogen activator (tPA) was administered to 57 MSU patients and the average time from 911 call-to-tPA was 42.5 min (±9.2), while EMS transported 73 patients who received tPA at 99.4 min (±35.7) (p<0.001). Seven MSU patients (12%) received tPA from 3.5 hours to 4.5 hours since last known well and would likely have been outside the window with EMS care. Endovascular thrombectomy was performed on 21 MSU patients with an average 911 call-to-groin puncture time of 99.9 min (±18.1), while EMS transported 54 patients who underwent endovascular thrombectomy (ET) at 133.0 min (±37.0) (p=0.0002). There was no difference between MSU and traditional EMS in modified Rankin score at 90-day clinic follow-up for patients undergoing intravenous thrombolysis or endovascular thrombectomy, whether assessed as a dichotomous or ordinal variable.ConclusionsMobile stroke care expedited both intravenous thrombolysis and endovascular thrombectomy. There is an ongoing need to show improved functional outcomes with MSU care.

Building a Mobile Stroke Unit Based on 5G Technology – A Study Protocol

Background: In-time treatment of acute stroke is critical to saving people’s lives and improving the quality of post-stroke life. A mobile stroke unit (MSU) with fifth-generation (5G) mobile networks strengthens the interaction of patient information and healthcare resources, thereby reducing response times and improving thrombolysis results. However, clinical evidence of better outcomes compared to regular care is still lacking.Method and Design: In this randomized controlled trial, 484 patients with acute stroke are allocated into the MSU and regular care groups. We establish medical records for each patient and conduct a follow-up of 90 days. The primary outcomes are functional results as defined by utility-weighted modified Rankin Scale (uw-mRS) 90 days after the incidence occurred, whereas secondary outcomes include the alarm to CT scan completed time, the alarm to treatment decision time, the alarm to thrombolytic time, quality of life, and symptomatic intracranial hemorrhage combined with NIHSS score as well as cost-effectiveness.Discussion: This study establishes an innovative MSU (based on 5G) to manage acute stroke, comparing its clinical and economic outcomes to regular care and informing decision-makers of the effectiveness of the stroke emergency system.Clinical Trial Registration: [http://www.chictr.org.cn/showproj.aspx?proj=63874], identifier [ChiCTR2000039695].

Abstract 1122‐000126: Mobile Stroke Unit Process Metrics in Large Vessel Occlusion Stroke Patients: BEST‐MSU Substudy

Introduction : Mobile Stroke Units (MSUs) speed thrombolytic treatment for acute ischemic stroke and improve clinical outcomes compared to standard management by Emergency Medical Services (EMS). However, MSU process metrics in the subset of patients with large vessel occlusions (LVOs) having endovascular thrombectomy (EVT) have yet to be optimized. Methods : A pre‐specified Benefits of Stroke Treatment Using a Mobile Stroke Unit (BEST‐MSU) substudy of tPA‐eligible stroke patients with imaging evident LVOs was conducted. The primary outcome was process metrics related to treatment times from stroke onset and first medical alert. Safety outcomes included rates of symptomatic intracerebral hemorrhage and procedural complications. Groups were compared using Chi‐square or Fisher’s exact tests for categorical variables, and Wilcoxon rank‐sum tests for continuous variables. Results : A total of 295 patients were included, 169 in the MSU group and 126 in the EMS group. Baseline characteristics were comparable between the groups, with the exception of baseline NIHSS (MSU mean 19.0 [IQR 13.0,23.0] vs EMS 16.0 [11.0, 20.0], p = 0.003). 92% of MSU and 87% of EMS LVO patients received tPA, and 78% and 85% went on to have EVT. Process metrics are detailed in Table 1. MSU LVO patients had faster tPA bolus from 911‐alert (MSU 45.0 minutes [40.0, 53.5] vs EMS 76.0 [64.0, 87.8], p<0.001), however the two groups had similar alert to groin puncture (MSU 142.5 [116.8, 171.0] versus EMS 131.5 [114.0, 159.8], p = 0.15). MSU patients spent more time on‐scene, (EMS arrival to ED arrival, 53.0 [45.0, 62.0] vs 27.0 [22.0, 33.0], p<0.001) however less time prior to EVT (door to groin puncture, 76.5 [54.8, 108.5] vs 94.0 [72.0, 123.0], p<0.001) with variable use of field CTAs and direct cath lab admission with ED bypass, yielding a net neutral result. The variability among site protocols is reflected in the range of median alert to groin puncture times (minimum 107.0 minutes, maximum 152.0). In the 222 patients undergoing EVT, median alert to recanalization time was 181.5 minutes [146.8, 225.5] in the MSU group and 190.5 [157.5, 227.5] in the EMS group (p = 0.47). Recanalization (Thrombolysis In Cerebral Infarction [TICI] 2b/3) was achieved in 76% of MSU and 70% of EMS (p = 0.32) with comparable rates of EVT complications (including hemorrhage, perforation, dissection, hematoma). 54% MSU and 44% of EMS LVO patients achieved good functional outcome (modified Rankin Scale [mRS] ≤ 2) at 90 days (p = 0.11). Conclusions : In tPA‐eligible LVO stroke patients, MSU management did not increase or expedite EVT treatment times as compared to standard EMS management. Future MSU processes should include field CTA with direct admission to cath labs to maximize the early treatment advantage this technology provides.

Telemedicine-enabled ambulances and mobile stroke units for prehospital stroke management

The recognition and management of stroke in the prehospital setting has become increasingly important to improve patient outcomes. Several strategies to advance prehospital stroke care have been developed, including the mobile stroke unit and the telemedicine-enabled ambulance—or “mini-MSU.” These strategies both incorporate ambulance-based audio-visual telemedicine evaluation with a vascular neurologist to facilitate faster treatment but differ in several areas including upfront and recurring costs, scalability or growth potential, ability to integrate into existing emergency medical services systems, and interoperability across multiple specialties or conditions. While both the mobile stroke unit and mini-mobile stroke unit model are valid approaches to improve stroke care, the authors aim to compare these models based on costs, scalability, integration, and interoperability in order to guide our prehospital leaders to find the best solutions for their communities.

High-resolution CT with arch/neck/head CT angiography on a mobile stroke unit

BackgroundMobile stroke units (MSUs) performance dependability and diagnostic yield of 16-slice, ultra-fast CT with auto-injection angiography (CTA) of the aortic arch/neck/circle of Willis has not been previously reported.MethodsWe performed a prospective observational study of the first-of-its kind MSU equipped with high resolution, 16-slice CT with multiphasic CTA. Field CT/CTA was performed on all suspected stroke patients regardless of symptom severity or resolution. Performance dependability, efficiency and diagnostic yield over 365 days was quantified.Results1031 MSU emergency activations occurred; of these, 629 (61%) were disregarded with unrelated diagnoses, and 402 patients transported: 245 (61%) ischemic or hemorrhagic stroke, 17 (4%) transient ischemic attack, 140 (35%) other neurologic emergencies. Total time from non-contrast CT/CTA start to images ready for viewing was 4.0 (IQR 3.5–4.5) min. Hemorrhagic stroke totaled 24 (10%): aneurysmal subarachnoid hemorrhage 3, hemorrhagic infarct 1, and 20 intraparenchymal hemorrhages (median intracerebral hemorrhage score was 2 (IQR 1–3), 4 (20%) spot sign positive). In 221 patients with ischemic stroke, 73 (33%) received alteplase with 31.5% treated within 60 min of onset. CTA revealed large vessel occlusion in 66 patients (30%) of which 9 (14%) were extracranial; 27 (41%) underwent thrombectomy with onset to puncture time averaging 141±90 min (median 112 (IQR 90–139) min) with full emergency department (ED) bypass. No imaging needed to be repeated for image quality; all patients were triaged correctly with no inter-hospital transfer required.ConclusionsMSU use of advanced imaging including multiphasic head/neck CTA is feasible, offers high LVO yield and enables full ED bypass.

Improving Outcomes After Stroke: From Stroke Units to Mobile Stroke Units

A proactive clinical approach to stroke care improved functional outcomes with implementation of specialized in-hospital stroke units, urgently delivered systemic thrombolysis, mechanical thrombectomy and most recently with mobile stroke units deployed in the field. An 18% absolute difference in outcomes as a shift across all modified Rankin Scale strata at 3 months in the recent Berlin study may not be explained by just 8.8% more patients treated within the golden hour for thrombolytic treatment from symptom onset. These findings parallel the findings in the largest controlled multi-center BEST-MSU trial (Benefits of Stroke Treatment Delivered Using a Mobile Stroke Unit) to date. A shortcoming in blinding of the investigators to the mode of transportation is similar to blinding to the endovascular treatment in PROBE (Prospective Randomized Open, Blinded End-Point) design used in thrombectomy trials. A faster access to stroke experts and brain imaging in the field for all patients suspect of stroke regardless symptom nature, severity, duration or resolution delivered by mobile stroke units is likely the reason for improved outcomes akin the impact observed in the initial multidisciplinary approach to in-hospital stroke units and reperfusion therapies delivery.